If any one is experiencing the issue described in this chrome bug report here on KDE, where for example you pop out a PiP window and a second Chrome icon appears, you can fix it in 2 ways. The first (better?) way is to create a KWin rule targeting the chrome class with a property of setting the desktop file to google-chrome (found under Appearance & Fixes).
Description=Google Chrome Desktop
desktopfile=google-chrome
desktopfilerule=3
wmclass=chrome chrome
wmclasscomplete=true
wmclassmatch=1
Alternatively you could change the StartupWMClass in the .desktop file from Google-chrome to chrome.
Looking at the chromium source code, I'm not entirely sure why this bug is occurring. Seems to be some widgets aren't get initialized with the correct class or desktop file name.
Pinned Comments
gromit commented on 2023-04-15 08:22 (UTC) (edited on 2023-05-08 21:42 (UTC) by gromit)
When reporting this package as outdated make sure there is indeed a new version for Linux Desktop. You can have a look at the "Stable updates" tag in Release blog for this.
You can also run this command to obtain the version string for the latest chrome version:
Do not report updates for ChromeOS, Android or other platforms stable versions as updates here.